ORIGIN AND SIGNIFICANCE OF CORN BELT MAIZE 129 



Dents, and inbred strains of Corn Belt dents. As has been shown previously 

 (Longley, 1938) and (Reeves, 1944), chromosome knobs may be an im- 

 portant tool in studying relationshii)S in maize. Our work with North Ameri- 

 can corn not only supports this contention, but suggests that knob data may 

 be even more important than has previously been supposed. 



The 8-10 rowed flint and flour varieties of New York, Pennsylvania, and 

 New England are nearly knobless. In the material we have examined, they 

 have to 2 knobs. These observations are in agreement with Longley's 

 earlier conclusions that maize varieties of the northern Indians were char- 

 acterized by having few knobs. Longley's material, however, included no 

 strains from northeastern United States — the area in which the flint an- 

 cestors of Corn Belt corn were highly concentrated. It is interesting, more- 

 over, to note that varieties from this segment of North America have even 

 fewer knobs than do the strains from most Northern Plains Indian tribes. 



In contrast, many more knobs were to be found in the open pollinated 

 varieties of Southern Dent corn. In these strains we have found numbers 

 ranging from 5 to 12, for those varieties representing the least contaminated 

 segment of present-day Southern Dent corn. These cytological data are in 

 complete agreement with the known facts regarding the history of Northern 

 Flints and Southern Dents. 



There seems little doubt that the Gourdseed-like Dents' of the southeast- 

 ern United States have stemmed directly from Mexico wiiere morphological- 

 ly and cytologically similar corns can be found even today. Likewise, we 

 have found in highland Guatemala varieties of maize with ear character- 

 istics strikingly similar to Northern Flints and with as few as three knobs. 

 Insofar as cytology is concerned, therefore, it is not at all difficult to visualize 

 a Guatemalan origin for Northeastern Flint corn. The Corn Belt inbreds 

 with which we have worked (Brown, 1949) have knob numbers of 1 to 8. 

 The distribution of numbers in these strains is almost exactly intermediate 

 between that of Northern Flints and Southern Dents (Fig. 8.2). This evi- 

 dence, based on a character which certainly has not been intentionally 

 altered by selection, strongly fortifies the archaeological and historical facts 

 pointing to a hybrid origin of Corn Belt dent corns. 



GENETIC EVIDENCE 



The genetical evidence for the origin of Corn Belt maize from mixtures 

 of Northern Flints and Southern Dents is of various kinds. In its totality, it 

 is so strong that, had we not been able to find the actual historical evidence, 

 we could have determined what had happened from genetic data alone. In 

 the first place we have demonstrated, by repeating the cross, that it is pos- 

 sible to synthesize Corn Belt dents from hybrids between Southern Dents 



I The name "Gourdseed" has been used since colonial times to describe the extremely- 

 long seeded, white Southern Dents, whose kernels are indeed not so diflferent in appear- 

 ance from the seeds of gourds of the genus Lagenaria. 



